Dictionary Attack Question
I've just upgraded my rig from a single nvidia gtx 660 to twin sapphire R9 290 vapor...  I had cracked a set of three unix SHA512 hashes with the nvidia card and managed to get all three accomplished in approximately 4 hrs with oclhashcat setup to use the nivida gpu.  I've since rerun the process with the R9s (linked)  and I can only get two of the three.  I've got it using a wordlist attack with the same wordlist used with the nvidia card.  I know the password is in there.  If i reduce the wordlist used to the three known passwords it ignores one of the passwords.  Is it possible to get a false solution?  and if not why would it miss the known password?
You maybe already cracked it, remove old potfile. If the problem persists, try again with latest beta version.